A technology for reducing and recycling treatment of
sludge of a
sewage treatment
plant comprises steps as follows:
sewage is treated with an air-floatation method, pretreated
sewage and primary
sludge are produced, the pretreated sewage is drained after biochemical treatment, treatment by a secondary
sedimentation tank and disinfection treatment, excess
sludge is separated in the secondary
sedimentation tank, the primary sludge and the excess sludge are concentrated, and concentrated sludge and a supernate are separated out; the concentrated sludge has an
anaerobic digestion reaction, digested sludge is subjected to
incineration or landfill treatment after
dehydration and
drying treatment, a filtrate is produced during
dehydration of the digested sludge, and
biogas is subjected to power generation and / or heat
recovery treatment after
dehydration and desulfurization treatment; the supernate and the filtrate are mixed for
nitrogen and
phosphorus removal. With the adoption of the technology, the primary
sedimentation effect of the sewage is improved, the yield of the primary sludge is increased, the primary sludge is removed before biochemical treatment, the yield of the excess sludge is decreased from the source, the primary sludge and the excess sludge are subjected to
anaerobic digestion treatment, the higher
organic matter transformation rate and the higher
biogas yield can be obtained, and the sludge can be reduced and recycled.